1. Field of the Invention
The present invention relates to pipe organs and in particular to a solid state, electronic relay or control system for use in such a pipe organ.
2. Description of the Prior Art
The pipe organ in its earliest and simplest forms consisted of a single group or "rank" of pneumatically activated pipes with individual ones of the pipes being operated by a single key of a keyboard or "manual". The individual pipes were coupled to a plenum or "wind chest" through a valve, individual ones of the valves being coupled mechanically to particular individual ones of the manual keys. As the musical demands on pipe organs grew, additional ranks of pipes and additional manuals were continuously added to the basic pipe organ. Each individual pipe of the organ was still, however, operated exclusively by a single key of the manual. This type of organ is referred to as a "tracker" organ.
The next significant development in the organ was the addition of the stop key, or simply, "stop", which enabled operation of more than one rank of pipes from each key of a manual. By selectively engaging one or more of the stops, a single key would energize one or more pipes, each in a different rank.
Various schemes evolved for playing more and more ranks of pipes from a single manual and to permit some degree of flexibility in the location of the manuals with respect to the organ pipes. All such organ architectures had one feature in common, however, in that any particular pipe could be played only from a single key of a single manual via a single stop. Thus, if it was desired to add an additional musical pitch or "voice" which could be activated or sounded from a certain manual, it was necessary to add an entire rank of additional pipes which were in turn connected to the manual via a stop.
Subsequently, the concept of a coupler was added to the pipe organ, the coupler being an additional control resembling a stop but which enabled operation of a particular group of ranks from a manual other than the manual with which the group was primarily associated or, in the alternative, to enable operation of the group from one or more additional keys of the same manual. These couplers were referred to as inter-manual and intra-manual couplers, respectively. This system did not, however, permit coupling of an individual stop activated rank to a different manual or different keys of the same manual individually, but rather required that all of the groups activated or "registered" for the particular manual by a stop were operationally coupled as a group.
Subsequently, the electro-pneumatic pipe organ was developed to eliminate the cumbersome pneumatic coupling and mechanical coupling mechanisms. In this development, the various bellows and pneumatic tubes connecting the various components were replaced with magnetic valves or "chest magnets" and the pneumatic tubes or linkages were replaced by electrical conductors. In the course of this development, it was realized that the then existing concept of one note, one stop, one pipe, represented an inefficient use of the organ pipes and that the coupler approach to expanding the versatility of the organ was still unnecessarily restrictive. For example, if an organ was equipped with a rank of pipes with the sound or "voice" of a flute and wherein the lowest pitch pipe was an 8 foot pipe, and it was desired to add a rank of pipes also having the sound or voice of a flute but with the lowest pitch being a 4 foot pipe, it is necessary in a classical organ, to add an entire sixty-one rank of pipes having a 4 foot pipe as the lowest pitch pipe in the rank. Ultimately, this led to the concept of "unification".
In its simplest terms, unification is the technique of expanding or extending pipes having a particular "voice" such that it, (the extended rank) can be used as if it were in fact two or more ranks of the same voice. For example, if a organ includes an 8 foot flute "voiced" rank of pipes, and it is desired to add a 4 foot flute voiced rank of pipes, it is only necessary to extend the treble end of the 8 foot rank by twelve (one octave) additional pipes. The rank now comprises 73 pipes instead of 61 and includes all of the pipes necessary for both an 8 foot and a 4 foot rank of flute voiced pipes. By operatively connecting the 61 lower (in pitch) pipes to a 61 key manual, and/or the 61 higher (in pitch) pipes to the manual, the organ is provided with substantially the same versatility as would be achieved by providing it with two separate 61 flute voiced ranks.
To effect such a system, each key of a manual is used to operate an electrical switch which in turn operates a note relay. Each of the note relays distributes control voltage to a plurality of secondary contacts and simultaneously establishes control isolation between the contacts when the note key is idle. A stop is derived by cabling a single contact from each note relay of a manual to a "stack switch" which is simply a 61 pole single throw switch operated from a stop switch of the console. The secondary contacts of the stack switches are connected to a multi-wire buss, the buss also being connected to the secondary contacts of other stack switches. The secondary contact buss is routed to the chest magnets controlling the pipes of a certain rank.
Thus configured, the relay system comprised an elaborate switching matrix. Thus, using the same example, if an organ has an 8 foot stop of a particularly voiced rank and it is decided to add a 4 foot stop of the same voice which can be operated from the same manual as the 8 foot rank, it is not necessary to install an entire additional rank as the case with classical organs. Rather, it is only necessary to extend the treble end of the existing 8 foot rank by 12 pipes, extend the treble end of the secondary switch buss by 12 wires, and install another key switch electrically displaced 12 wires from the first one. This results in a system having a high degree of musical versatility.
Further developments in the art have been directed to improvement of the basic "unification" concept and have included efforts to combine switches and to adapt solid state electronic technology to the switching operations to eliminate mechanical contacts and the like. Nonetheless, present pipe organs still incorporate the traditional parallel-processing of signals from the manual keys to the organ pipes. Thus, in a typical installation which might include four manual keyboards and more than a dozen ranks of organ pipes, the number of connections that must be routed from the manual to the pipes is extremely great. Further, consideration of the number of individual connections that must be made to route these signals from key switches through stack switches, couplers, stops, chest magnets, etc., renders even modern day versions of such a system extremely cumbersome and difficult to install and maintain. Additionally, the cost of such an installation and the time required for same is high and often prohibitive. Each organ also tends to be a "custom" installation and changes in the organ configuration are difficult at best.
Some recent efforts have been made to produce a control system which incorporates the concept of multiplexing whereby the number of wires interconnected between the manuals and the organ pipes is substantially reduced. However, even in these systems, the concept of unification has received little if any attention inasmuch as most of these installations are applied to classical or liturgical type organs where unification is not generally utilized. Thus, the ultimate goal of unification, -increased versatility of the organ-, remains to be improved. Further, the accessory functions such as pizzicato, reiteration, and sostenuto must be retained to provide an organ having full musical capacity.